I don't know what I did or what I should do?

Me & this guy have been trying to get together for over a year.In about September we were finally able to & it was going amazingly.I went overseas, but we still had plans for when i get back, adventures to take together. We were being cute & he said he loved me.Then he started distancing himself. This stressed me out & i made a deal of it.The last time i talked to him he said 'life is so hard'.I said i would give him space to consider everything. It's only been a few days, but i'm struggling. A girl wrote some inside joke on his wall, he has so many friends who are girls, but still jealously rears its ugly head.I don't know why he would suddenly change his mind & if he does then i guess that means he never loved me to begin with.